1. Field of the Invention
The present invention relates to a Digital Video Broadcasting-Handheld (DVB-H) terminal, and more particularly to a method and a DVB-H terminal for ensuring the integrity of a container in the case where the container is to be transmitted from a DVB-H server to the DVB-H terminal.
2. Description of the Related Art
DVB-H implies technical standards which have been established for the purpose of improving the receptibility of mobile Digital TeleVision (DTV), and the letter ‘H’ represents ‘Handheld.’ The standards support mobile multimedia broadcasting, which provides high quality audio and image services anytime and anywhere, even while driving or walking.
A service model using this DVB-H has the following configuration. Above all, a sending side is configured with a network through which common carriers and broadcasters interact with one another according to standards of the Digital Video Broadcasting-Universal Mobile Telecommunications System (DVB-UMTS). The broadcasters deliver compressed data to a DVB-H terminal (hereinafter, referred to as a “terminal”) in a transmission scheme of the DVB-H on the basis of the standards of the Digital Video Broadcasting-Advanced Video Coding (DVB-AVC). The terminal communicates with the common carriers according to communication standards such as the Digital Video Broadcasting-Universal Mobile Telecommunications System/Global System for Mobile communication (DVB-UMTS/GSM), and is able to deliver information on the receiving-side to the broadcasters in real time via a communication network.
Most of the information pertinent to the broadcasting is included in an Electric Service Guide (ESG) in DVB-H, and by receiving the ESG, the terminal acquires information required to receive a service provided by a service provider by receiving an ESG stream. When a user has selected a specified service, by using the acquired information, the terminal gains access to a transmitted data stream so as to provide the service, and then receives data. The information required for the terminal to gain access to the data stream is transmitted by using ESG fragments.
According to the ESG data model, fragments of the ESG data, classified by fragments, are grouped into one fragment set containing several fragments, and are then included in one container, which is considered and transmitted as one object during a flute session. Herein, the terminal can receive a container including data by using a scheme called flute carousel which refers to a scheme in which the terminal receives a container if a DVB-H transmission server continues to send the container on the air over different periods of time.
The above terminal can offer the digital broadcasting services only if the terminal always must receive the ESG data. The terminal also experiences the occurrence of a service interruption due to various kinds of factors while receiving data needed to execute the digital broadcasting services. Accordingly, in a case where the terminal does not receive a container or does not receive data caused by unstable reception conditions, the terminal must wait until the DVB-H server transmits normal data again.
In a case where data is lost or reception is completed while receiving data by using the flute carousel scheme, the terminal performs a continuous download by using the following method. A flute packet includes sequence numbers classifying files, and the terminal makes decisions after detecting the sequence numbers. When a file is transmitted, the file is divided into blocks each of which is divided into symbols, and a unit of symbols is matched with the size of the flute packets transmitted via a network. At this time, each symbol has a sequence number representing itself. Each block has information on how many symbols it includes, connects symbols on receiving the symbols by using a list to which each block is internally linked, and finally merges the connected symbols. Therefore, the container can be subsequently received when the transmission order of an interrupted container comes only after receiving other containers of the DVB-H flute carousel. This method has features that are almost similar to features of a method for a continuous download of a general Peer-to-Peer (P2P) processing.